Particles containing absorbed liquids and methods of making them

ABSTRACT

Perfume is absorbed within organic polymer particles which have a further polymer at their exterior. The further polymer incorporates free hydroxyl groups and serves to promote deposition of the particles from a wash or rinse liquor. The further polymer may be part of an encapsulating shell, but more conveniently is used as a stabiliser during polymerisation of the particles. Highly hydrolysed polyvinyl alcohol is preferred.

This invention relates to particles containing absorbed liquids. Anexample of such a liquid is a perfume; another is a sunscreening agent.They are useful in for example detergent, personal care, cosmetic andsunscreening products.

SUMMARY OF PRIOR ART

There have been a number of proposals for absorbing perfume onto a solidcarrier material, and various reasons for doing so. In a number ofinstances, the objective of such proposals has been merely to convertliquid perfume into a solid form which can more readily be incorporatedinto another product. It has been asserted that such carrier substancesmay serve to protect the perfume from loss during storage or protect itfrom contact with other constituents of a composition.

Examples of disclosures of such carriers for perfume are GB-A-1306924,U.S. Pat. No. 3,449,266, U.S. Pat. No. 3,909,461, U.S. Pat. No.4,536,315, U.S. Pat. No. 4,539,135, U.S. Pat. No. 4,713,193,GB-A-2066839, EP-A-332259, EP-A-332260 and JP-A-63/79662. In many ofthese documents the carriers are inorganic materials.

EP-A-535942 and EP-A-536942 are concerned with inorganic carriermaterials which serve to reduce the vapour pressure of absorbed perfume.

As pointed out in those documents, a carrier material which reduces theperfume vapour pressure over the solid carrier but releases the perfumeon contact with water can be useful to avoid giving excessive perfumeodour to a concentrated product, yet provide the required concentrationof perfume in a wash or rinse liquor.

EP-A-285694 is one of a series of documents concerned with porous crosslinked polymers obtained by polymerisation around droplets of a liquidsubstance which may subsequently be removed. These porous polymers canact as carriers for a variety of liquids. They are used in products forapplication to the skin, and give controlled release of the liquid tothe skin.

U.S. No. Pat. 4,842,761 discloses composite particles in which onepolymer is embedded within another. These particles are used as perfumecarriers in laundry detergents and provide controlled release ofperfume.

THE INVENTION

We have now found that the retention or controlled release of liquidsfrom particles can be improved by imbibing the liquid into particlescontaining organic polymer having at the surface of the particles afurther polymer with free hydroxyl groups. Such polymer enhancesdeposition of the particles and by doing so also enhances deposition ofthe imbibed liquid. The use of such particles can enhance deposition ofthe liquid, it can retard the evaporation of deposited liquid and canalso enhance the extent to which deposited liquid survives a subsequentdrying step.

Accordingly, the present invention provides particles containing organicpolymer, which are insoluble in water, with liquid imbibed by theparticles, the particles having at their exterior, a polymer whichincorporates free hydroxy groups. This polymer will be referred to belowas a "hydroxy functional polymer".

The invention also provides products which are compositions or articlescontaining particles according to the invention together with otheringredients. The quantity of the particles will depend on the nature ofthe product but will generally provide liquid in an amount within thebroad range 0.1 to 10% by weight. In particular such products may bepersonal washing compositions, fabric detergent compositions, othercleaning compositions, fabric conditioner compositions, "leave-on" hairand skin care compositions or sunscreening compositions incorporatingsuch liquid-containing particles.

As will be explained in greater detail below, the organic polymerparticles are solid (but possibly porous solid) particles into whichliquid is absorbed by imbibition. Polymer capsules may enclose a solidcore into which perfume is absorbed.

The particles themselves are insoluble in water, so that they can bedeposited from an aqueous wash or rinse liquor.

The hydroxy functional polymer at the exterior of these particles mayform, or be included within a coating or incomplete coating on theseindividual particles. The hydroxy functional polymer is preferablynonionic or cationic. It will be explained below that it generallyconstitutes between 1 and 25% of the weight of the particles, usuallybetween 1 and 10%.

Cationic functionalities may additionally be present at the exterior ofthe particles, and may be provided by the hydroxy functional polymer orotherwise. Presence of cationic monomers has a tendency to increaseparticle size.

Particle Size

Polymer particles used in this invention desirably have an averageparticle size of at least 10 μm, better at least 20 μm or 30 μcm, forease of handling. Also, we have observed that the rate of release ofliquid may be faster than desired if the particles are of very smallsize such as average size of 1 μm. The polymer particles desirably havean average size not larger than 150 μm, better not over 125 μm so thatthe particles are not easily visible after deposition.

For particles intended to be used in fabric washing or conditioning, itis especially preferred to use particles with a mean size of at least 40μm, e.g. 40 to 100 μm to retain perfume in the particles and provideslow liquid release.

For particles intended for other products, e.g. personal washingproducts, a faster rate of release may be desired than with fabricsproducts, although retention of liquid and delay in release for somehours is still desirable, consequently a smaller particle size may beadvantageous, such as a mean size in the range from 10 to 50 μm.

Polymerisation techniques generally produce a range of particle sizes.For this invention it is desirable that a high proportion of theparticles lie between the above limits on particle size. Thus, whenparticles are intended for fabric treatment, preferably 90% or more ofthe particles are larger than 30 μm. Preferably also 90% or more of theparticles are not larger than 150 or even 125μ. Better, 95% or more arenot larger than 125 or even 100 μm.

To achieve these criteria, it may be necessary to sieve the particlesand thereby separate oversized and/or undersized particles. An importantaspect of reducing the amount of emulsion polymer formed (broadlyspeaking, polymer beads of a size below 10 μm) is to use an initiatorsystem that is substantially insoluble in the aqueous phase, so as toprevent initiation of monomer molecules held in micelles. Suitable waterinsoluble initiators include azo compounds such asazobisisobutyronitrile (AIBN) and higher alkyl peroxides.

Hydroxy Functional Polymer

This polymer bearing hydroxy groups and located at the exterior of theparticles serves to enhance deposition onto (or retention on) skin,hair, hard surfaces especially vitreous surfaces and fabric.

This polymer is desirably such that at least 80% of the monomer residuesin the polymer contain at least one free hydroxy group able toparticipate in hydrogen bonding. The polymer is preferably nonionic andsuch that, in its pure state, it is water-soluble. However, whenattached to the exterior of the particles, it does not render them watersoluble. The attachment is such that the polymer is not completelyremoved upon contact with water. It may be chemically bonded with thecore polymer.

The preferred polymer is polyvinyl alcohol.

As is well known, polyvinyl alcohol cannot be prepared directly bypolymerisation, and is obtained by the hydrolysis of polyvinyl acetate.This hydrolysis generally stops before completion, and polymers withvarying amounts of hydrolysis are commercially available.

We have found that deposition of particles, especially onto fabric, isbetter when the polyvinyl alcohol exhibits a substantial level ofhydrolysis.

We may therefore prefer to use polyvinyl alcohol which is 85 to 100%hydrolysed i.e. in which 85 or 88 to 100% of the acetate residues havebeen removed by hydrolysis. More preferably, the polyvinyl alcohol is atleast 90% better at least 96% hydrolysed, e.g. 96 to 99% hydrolysed.

Another possible polymer is a copolymer of polyvinyl alcohol, availablethrough hydrolysis of the corresponding copolymer of vinyl acetate. Forexample a copolymer of vinyl acetate and vinyl formamide, with a highproportion of vinyl acetate can by hydrolysed to a copolymer of vinylalcohol and vinyl formamide. Further hydrolysis of such a polymerconverts the formamide residues to amine groups, giving a cationiccopolymer of vinyl alcohol and vinyl amine.

Another category of polymers which can be used is cellulose andchemically modified cellulose where the modification does not greatlyreduce the number of hydroxyl groups present. Examples of polymers inthis category are hydroxyethyl cellulose, and hydroxypropyl cellulose.

Hydroxyethyl cellulose is available commercially and is made bytreatment of cellulose with sodium hydroxide, followed by reaction withethylene oxide. Another possibility is cellulose which has beenchemically modified by the introduction of cationic substituent groups.

It is a characteristic of many grades of polyvinyl alcohol and ofhydroxy ethyl cellulose that free hydroxy groups constitute more than20%, often more than 25% of the weight of the polymer.

Solid Particles

This invention uses polymer particles which are solid--although they maybe porous as well as solid--rather than particles in the form of hollowcapsules.

Advantages of solid particles over capsules are that the desired sizerange is accessible, and that the polymerisation reaction can be carriedout in the absence of the liquid.

The particles could possibly be porous particles made by polymerisationaround a liquid pore-forming agent, as taught in EP-A-285694. However,we have found it to be unnecessary to include such a pore-forming agent.Polymers formed by simple polymerisation of a monomer mixture are ableto absorb and carry perfume.

Preferred polymer particles may be formed by the polymerisation of vinylmonomers, with some cross linking and/or chain branching agent includedin the monomers which are polymerised, so that some cross links areformed between the polymer chains. If a cross linking agent is used, theproportion of cross linking may be low, so that after polymerisationthere may be some polymer chains which remain entirely linear and arenot cross linked to any other chains.

A number of vinyl monomers containing a single carbon-carbon double bondmay be used. One suitable category of monomers is the esters of acrylicand alkyl acrylic acids, of formula ##STR1## where R₁ is hydrogen orstraight or branched alkyl of 1 to 6 carbon atoms, preferably 1 to 3carbon atoms and R₂ is straight or branched alkyl of 1 to 6 carbonatoms, preferably 3 to 6 and most preferably 3 or 4 carbon atoms in astraight or branched chain.

Specific examples of suitable monomers are isobutyl methacrylate (whichis particularly preferred), n-butyl acrylate, n-butyl methacrylate,isobutyl acrylate, n-propyl acrylate and iso-propylmethacrylate. Lesspreferred is methyl methacrylate.

Another suitable monomer is styrene.

It is possible to use simple linear polymers. However, these can giveparticles which are somewhat sticky, and it is usually convenient tointroduce some cross-linking or chain branching.

Cross linking between polymer chains formed from the above monomers canbe achieved by including in the monomer mixture a small proportion--forexample less than 10%, preferably as little as 5% or 1%--of a monomerwith two carbon-carbon double bonds. The use of such a material toprovide cross linking is well known in other applications of polymers,although it is usual to introduce a greater proportion of cross linkingthan is required for this invention. Examples of this type of crosslinking agent are divinyl benzene, diesters formed between acrylic acidand diols, such as 1,4 butane diol diacrylate, and higher esters formedbetween acrylic acid and polyols--which may be sugars.

Chain branching can be introduced by including among the monomers ahydroxyalkyl monomer of formula ##STR2## where R₁ is as specified aboveand R₃ is alkyl of 1 to 6 carbon atoms bearing at least one hydroxygroup, preferably 3 to 4 carbon atoms in a straight or branched chainand bearing a single hydroxy group. These monomers undergo a sidereaction during the course of polymerisation, and this side reactionproduces chain branching. When there is chain branching without crosslinking, it is suitable that hydroxyalkyl monomer of the above formulaprovides from 10 to 40% by weight of the monomer mixture.

Suitable hydroxyalkyl acrylate monomers are hydroxypropyl methacrylate,hydroxybutylacrylate, and hydroxyethylacrylate.

Attachment of a polymer with hydroxy groups, notably polyvinyl alcohol,at the exterior of the particles, can be achieved by polymerising themonomers in the presence of the polyvinyl alcohol (or other polymer withhydroxy groups) using the technique of suspension polymerisation.

Suspension polymerisation is a process in which the organic monomers areformed into a suspension in an aqueous phase, and polymerised.Polymerisation of each suspended droplet leads to a bead of polymer.

It is customary to stabilise the suspension by incorporating astabilising agent in the aqueous phase before adding the monomer.Polyvinyl alcohol is known to act as a stabiliser.

Thus, a typical polymerisation procedure will commence by forming anaqueous solution of the hydroxy functional polymer which acts asstabilising agent, together with a polymerisation initiator, in areaction vessel. Then while agitating the contents of the reactionvessel, the organic monomers are progressively fed in so that themonomers become dispersed in the aqueous phase and polymerise therein.The addition of monomers can be continued until the mixture in thereaction vessel is a slurry of polymer beads containing about 30% byweight of polymer.

In a possible variation of this procedure some of the monomer isdispersed in the aqueous solution of stabilising agent before anypolymerisation initiator is added. In another possible variation themonomers are emulsified in water before they are added to the reactionvessel.

Suspension polymerisation typically produces polymer beads with adiameter larger than 100μ. Smaller particle sizes in the range of50-100μ can be obtained by increasing the amount of stabiliser in theaqueous phase, or by increasing the amount of agitation, or both.

Polymerisation may be carried out using a combination of polyvinylalcohol and a second stabilising agent which may or may not be a secondhydroxy-functional polymer. Examples of materials which can serve as asecond stabilising agent include sodium lauryl sulphate, both of whichare anionic surfactants, also nonionic surfactants with HLB of 8 andabove, such as C₁₃ /C₁₅ alcohol ethoxylated with 3 to 11 ethylene oxideresidues, and sorbitan ester surfactants of similar HLB.

The amount of hydroxy functional polymer present in solution as astabilising agent will generally be between 1% and 5% by weight of theaqueous phase in which polymerisation occurs. Larger amounts can also beused.

The amount may well be between 3% and 15% by weight of the monomersundergoing polymerisation, possibly between 5% and 10%.

Observation by microscopy of such particles showed the hydroxyfunctional polymer to form a coating or incomplete coating of theparticles, from which it can be estimated that the amount of hydroxyfunctional polymer attached to the particles was at least 1% by weightof these particles after (and also of course before) the incorporationof perfume.

Suspension polymerisation can be used to produce linear polymers, orcross linked polymers. The presence or absence of cross linking isdetermined by the monomers which are used.

As mentioned above, a molecule with more than one carbon-carbon doublebond can serve as a cross linking agent. When used, a suitable amount ofsuch cross-linking agent is not over 5 mole % of the monomer mixture,e.g. in a range from 0.5 to 3 mole %.

Hydroxy substituted acrylate esters can also lead to cross-linking. Themechanism by which they do so is a side reaction which is not fullyunderstood. When used, a suitable amount may lie in a range from 3 to 30mole % of the monomer mixture. Preferably 10 to 30 mole %.

After the manufacture of the particles by polymerisation, the directproduct is in the form of an aqueous slurry. If desired, the particlesmay be separated from the aqueous phase by filtration or centrifuging,possibly followed by drying.

Another possible route for the production of polymer particles isemulsion polymerisation to yield an aqueous emulsion of very smallpolymer particles (typically of sub-micron size) followed by a dryingstep to agglomerate these particles into larger particles with a size ofat least 20μ.

Absorption of perfume by the particles can be brought about simply bybringing the perfume and the particles into contact, and allowing themto stand. This may be done by mixing perfume with the particles afterthey have been separated from the aqueous phase, or it may be done bymixing perfume into an aqueous slurry of the particles and allowing themixture to equilibrate. It can be done by mixing the particles andperfume separately into an aqueous liquid product and allowing thatmixture to equilibrate.

Encapsulated Particles

A further possibility is to encapsulate a "core" of polymer as describedabove, with aminoplast resin, while providing hydroxy-functional polymerat the exterior of the capsules, and absorb perfume within the core.

Several typical procedures are available to produce such encapsulatedpolymer. One procedure is to form polymer beads, for example of anacrylate polymer, as described earlier, and disperse this organicmixture in an aqueous solution containing the hydroxy functional polymerand urea-formaldehyde precondensate. The mixture is agitated to keep theorganic mixture in suspension. While maintaining solution temperaturebetween 20° C. and 90° C., acid is then added to catalyse polymerisationof the dissolved urea-formaldehyde precondensate. If the solution israpidly agitated during this polymerisation step, shells ofwater-insoluble, urea-formaldehyde polymer form around and encapsulatethe dispersed organic mixture and molecules of the hydroxy-groupcontaining polymer are incorporated in and at the exterior of theseshells. Melamine-formaldehyde precondensate can be used in place ofurea-formaldehyde, and may be preferred.

Another procedure is to form encapsulated core polymer, in the absenceof perfume, and subsequently allow perfume to diffuse through the shell,into the core polymer. We have found that absorption of perfume ispossible through a thin shell, even though a thicker hollow shell iscapable of retaining liquid perfume. Suitably the weight of polymerforming the shell is less than the weight of polymer forming the core,and the shell to core weight ratio may lie in a range from 1:3 to 1:20,better 1:5 to 1:20.

Hydroxy functional polymer will generally provide a substantialproportion of the shell, yet constitute from 1% to 25% of the capsules.

For this procedure it has been found preferable to encapsulate monomerwithin an aminoplast shell, then polymerise the monomer to form a(preferably solid) core of polymer within the shell. Less preferred isto partially polymerise the core before encapsulation.

It is also possible to encapsulate a mixture of liquid monomer andfragrance, then polymerise. However, this necessarily exposes perfume tothe polymerisation reaction, whereas absorption of perfume through theshell into a previously polymerised core does not.

When a product contains particles in which perfume is absorbed withinpolymer which is encapsulated by a thin shell, perfume can diffusethrough the shell, and can be released without rupture of the shell,although the release and dispersion of perfume will be slower than forneat perfume. Thus, encapsulated polymer with absorbed perfume canprovide deposition and retarded release of perfume similarly to the(preferred) arrangement when perfume is absorbed in polymer beads whichhave hydroxy functional polymer directly at their exterior.

Perfume

As is well known, a perfume normally consists of a mixture of a numberof perfumery materials, each of which has a fragrance. The number ofperfumery materials in a perfume is typically ten or more. The range offragrant materials used in perfumery is very wide; the materials comefrom a variety of chemical classes, but in general are water-insolubleoils. In many instances, the molecular weight of a perfumery material isin excess of 150, but does not exceed 300.

The perfumes used in the present invention can be mixtures ofconventional perfumery materials. Perfumery materials which may be usedinclude: acetyl cedrene, 4-acetoxy-3-pentyltetrahydropyran,4-acetyl-6-t-butyl-1,1-dimethylindane, available under the trademark"CELESTOLIDE", 5-acetyl-1,1,2,3,3,6-hexamethylindane, available underthe trademark "PHANTOLIDE",6-acetyl-1-isopropyl-2,3,3,5-tetramethylindane, available under thetrademark "TRASEOLIDE", alpha-n-amylcinnamic aldehyde, amyl salicylate,aubepine, aubepine nitrile, aurantion, 2-t-butylcyclohexyl acetate,2-t-butylcyclohexanol, 3-(p-t-butylphenyl)propanal, 4-t-butylcyclohexylacetate, 4-t-butyl-3,5-dinitro-2,6-dimethyl acetophenone,4-t-butylcyclohexanol, benzoin siam resinoids, benzyl benzoate, benzylacetate, benzyl propionate, benzyl salicylate, benzyl isoamyl ether,benzyl alcohol, bergamot oil, bornyl acetate, butyl salicylate,carvacrol, cedar atlas oil, cedryl methyl ether, cedryl acetate,cinnamic alcohol, cinnamyl propionate, cis-3-hexenol, cis-3-hexenylsalicylate, citronella oil, citronellol, citronellonitrile, citronellylacetate, citronellyloxyacetaldehyde, cloveleaf oil, coumarin,9-decen-1-ol, n-decanal, n-dodecanal, decanol, decyl acetate, diethylphthalate, dihydromyrcenol, dihydromyrcenyl formate, dihydromyrcenylacetate, dihydroterpinyl acetate, dimethylbenzyl carbinyl acetate,dimethylbenzylcarbinol, dimethylheptanol, dimethyloctanol, dimyrcetol,diphenyl oxide, ethyl naphthyl ether, ethyl vanillin, ethylenebrassylate, eugenol, geraniol, geranium oil, geranonitrile, geranylnitrile, geranyl acetate,1,1,2,4,4,7-hexamethyl-6-acetyl-1,2,3,4-tetrahydronaphthalene, availableunder the trademark "TONALID",1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-2-benzopyran,available under the trademark "GALAXOLIDE", 2-n-heptylcyclopentanone,3a,4,5,6,7,7a-hexahydro-4,7-methano-1(3)H-inden-6-ylpropionate,available under the trademark "FLOROCYCLENE",3a,4,5,6,7,7a-hexahydro-4,7-methano-1(3)H-inden-6-ylacetate, availableunder the trademark "JASMACYCLENE",4-(4'-hydroxy-4'-methylpentyl)-3-cyclohexenecarbaldehyde,alpha-hexylcinammic aldehyde, heliotropin, Hercolyn D, hexyl aldone,hexyl cinnamic aldehyde, hexyl salicylate, hydroxycitronellal, i-nonylformate, 3-isocamphylcyclohexanol, 4-isopropylcyclohexanol,4-isopropylcyclohexyl methanol, indole, ionones, irones, isoamylsalicylate, isoborneol, isobornyl acetate, isobutyl salicylate,isobutylbenzoate, isobutylphenyl acetate, isoeugenol, isolongifolanone,isomethyl ionones, isononanol, isononyl acetate, isopulegol, lavandinoil, lemongrass oil, linalool, linalyl acetate, LRG 201, 1-menthol,2-methyl-3-(p-isopropylphenyl)propanal,2-methyl-3-(p-t-butylphenyl)propanal, 3-methyl-2-pentyl- cyclopentanone,3-methyl-5-phenyl-pentanol, alpha and beta methyl naphthyl ketones,methyl ionones, methyl dihydrojasmonate, methyl naphthyl ether, methyl4-propyl phenyl ether, Mousse de chene Yugo, Musk ambrette, myrtenol,neroli oil, nonanediol-1,3-diacetate, nonanol, nonanolide-1,4, nopolacetate,1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethyl-2-acetyl-naphthalene,available under the trademark "ISO-E-SUPER", octanol, Oppoponaxresinoid, orange oil, p-t-amylcyclohexanone,p-t-butylmethylhydrocinnamic aldehyde, 2-phenylethanol, 2-phenylethylacetate, 2-phenylpropanol, 3-phenylpropanol, para-menthan-7-ol,para-t-butylphenyl methyl ether, patchouli oil, pelargene, petitgrainoil, phenoxyethyl isobutyrate, phenylacetaldehyde diethyl acetal,phenylacetaldehyde dimethyl acetal, phenylethyl n-butyl ether,phenylethyl isoamyl ether, phenylethylphenyl acetate, pimento leaf oil,rose-d-oxide, Sandalone, styrallyl acetate,1,1,4,4-tetramethyl-6-acetyl-7-ethyl-1,2,3,4-tetrahydronaphthalene,available under the trademark "VERSALIDE", 3,3,5-trimethyl hexylacetate, 3,5,5-trimethylcyclohexanol, terpineol, terpinyl acetate,tetrahydrogeraniol, tetrahydrolinalool, tetrahydromuguol,tetrahydromyrcenol, thyme oil, trichloromethylphenylcarbinyl acetate,tricyclodecenyl acetate, tricyclodecenyl propionate, 10-undecen-1-al,gamma undecalactone, 10-undecen-1-ol, undecanol, vanillin, vetiverol,vetiveryl acetate, vetyvert oil, acetate and propionate esters ofalcohols in the list above, aromatic nitromusk fragrances, indane muskfragrances, isochroman musk fragrances, macrocyclic ketones,macrolactone musk fragrances, and tetralin musk fragrances.

Perfumes frequently include solvents or diluents, for example: ethanol,isopropanol, diethylene glycol monoethyl ether, dipropylene glycol,diethyl phthalate and triethyl citrate.

Perfumes which are used in this invention may, if desired, havedeodorant properties as disclosed in U.S. Pat. No. 4,303,679, U.S. Pat.No. 4,663,068 and EP-A-545556.

If the polymer particles are solid particles which are impregnated withliquid after manufacture, we have found that the absorption of liquidcan be enhanced by choosing materials with a hydrophobic character ormixing a hydrophobic oil into the perfume. Examples of hydrophobic oilswhich can enhance perfume uptake are dibutylphthalate, alkane mixturessuch as isoparaffin and di(C₈ -C₁₀ alkyl) propylene glycol diester.

Liquid Properties

When the preferred solid particles are allowed to absorb liquid, theycan absorb a surprising quantity, often in excess of their own weight.

We prefer to use a polymer:liquid weight ratio in a range from 4:1 to1:10, especially from 2:1 or 3:2 up to 1:3 or 1:4.

When perfume is encapsulated in microcapsules, for instance capsules ofaminoplast resin, the weight ratio of shell polymer to perfume may liein a range from 1:30 or 1:20 to 1:2 or 1:1.

Perfume Release

If the polymer particles are solid particles impregnated with perfume,then after deposition of the particles onto a surface, such as fabricsurface, hair, skin, glass etc, the perfume will be released from thesurface by evaporation from the particles. We have observed that theprofile of evaporation from the particles is similar to the profile ofevaporation from neat perfume oil itself. As is usual, the more volatile"top note" materials evaporate first. In consequence the character ofthe fragrance is not greatly changed by absorption into the polymerparticles.

However, we have observed that some perfume components are retained inthe deposited particles during the drying, whereas they are lost byevaporation during drying if deposited directly on fabric withoutpolymer present. Thus the polymer particles may alter the character ofthe fragrance retained on a surface after drying, so that it moreclosely resembles the original perfume oil.

If the polymer particles are capsules containing liquid perfume, theperfume may be trapped within the capsules until the capsules rupture(although we prefer capsules with a thin wall, to allow the perfume todiffuse out through the intact wall). Rupture of capsules may take placeduring drying, notably during tumble drying of fabrics, or it may takeplace during handling and ironing of fabrics.

Fabric Detergent Composition

Perfume-carrying particles of this invention may be incorporated into adetergent composition for fabric washing. Such a composition may be insolid form, notably a particulate or compressed solid composition, ormay be in liquid form, notably with an aqueous or non-aqueous liquidphase with or without suspended solid.

Surfactants useful as detergent active in the detergent compositionsherein include well-known anionic, nonionic, amphoteric and zwitterionicsurfactants. Typical of these are the alkyl benzene sulphonates, alkylsulphonates, alkyl- and alkyl ether sulphates, primary alkyl sulphates,alkoxylated alcohols, alpha-sulphonates of fatty acids and of fatty acidesters, alkyl betaines, and alkyl polyglycosides all known in thedetergent art.

Detergent active is preferably present in a quantity of at least 5% or10% by weight of a composition, and may well be in a quantity notexceeding 50% or 40% by weight. Concentrated solid detergentcompositions will generally contain detergent active in a quantity from10% to 50% by weight of the composition. Liquid compositions willtypically contain from 5% to 30% by weight surfactants.

Detergency builders are materials which function to soften hard water bysolubilisation or other removal of calcium and to a lesser extentmagnesium salts responsible for water hardness compounds, especiallyexemplified by sodium tripolyphosphate. A further water solubleinorganic builder compound is sodium carbonate which is generally usedin conjunction with a seed crystal to accelerate the precipitation ofcalcium carbonate. Common insoluble inorganic detergency builders arezeolites. Organic detergency builders such as sodium citrate andpolyacrylate can also be used. The detergency builder component of adetergent composition will as mentioned generally comprise from 5 to80%, preferably from 5 to 10% to 60% by weight of the detergentcomposition. As is well known, many detergent compositions avoidphosphate builders.

A liquid composition will typically contain 5% to 40% by weight ofwater-soluble builder salt, partially dissolved and partially suspendedin an aqueous liquid phase.

Other ingredients which are customarily included in a detergentcomposition, although not necessarily all together, include bleaches,bleach activators, alkaline silicate, soil release agents,anti-redeposition agents such as sodium carboxymethyl cellulose,enzymes, fabric softening agents including softening clays, fluorescentbrighteners, antifoam agents or conversely foam boosters and filler suchas sodium sulphate.

A detergent composition will generally contain from 0.1 to 3% by weightof perfume, more usually not over 1.5 or 1%, at least partially carriedby perfume particles according to this invention. Perfume carryingparticles of this invention are preferably added to a detergentcomposition after any manufacturing steps involving heat (e.g. spraydrying). Thus perfume carrying particles according to this invention maybe added to a detergent composition, typically by mixing them into thepreformed particulate or liquid detergent composition. They may be addedas dry particles, or as an aqueous slurry. If the composition is aparticulate solid, the water content of a slurry may be absorbed byother constituents of the detergent composition.

Fabric Conditioners

Perfume-carrying particles of this invention may be incorporated infabric conditioning products used during rinsing of fabrics. The mainbenefits delivered by such products are softness, fragrance andanti-static. Softness is usually the most important.

A fabric softening product contains at least one softening agent whichfunctions to give the fabric a softer handle. Frequently such agentsalso provide an anti-static benefit. Such agents are usually cationic,but may be nonionic, amphoteric or zwitterionic materials.

Many fabric softening products take the form of compositions intended tobe added to rinse water. The fabric softening agents are then materialswith low solubility in water, and which deposit on the fabrics.Typically the solubility in acidified water at 20° C. is less than 10g/liter, preferably less than 1 g/liter. When added to rinse water suchmaterials form a dispersed phase which is then able to deposit onfabrics which are being rinsed in the water.

Many commercially important fabric softening agents are organiccompounds containing quaternary nitrogen and at least one carbon chainof 6 to 30 carbon atoms, e.g. in an alkyl, alkenyl or aryl substitutedalkyl or alkenyl group with at least six aliphatic carbon atoms.

Other fabric softening agents are the corresponding tertiary amines andimidazolines, other aliphatic alcohols, esters, amines or carboxylicacids incorporating a C8 to C30 alky, alkenyl or acyl group, includingesters of sorbitan and esters of polyhydric alcohols, mineral oils,polyols such as polyethylene glycol, and also clays.

Some specific instances of fabric softening agents are:

1) Acrylic Quaternary Ammonium Compounds of the Formula (I) ##STR3##wherein each Q₁ is a hydrocarbyl group containing from 15 to 22 carbonatoms, Q₂ is a saturated alkyl or hydroxy alkyl group containing from 1to 4 carbon atoms, Q₃ may be as defined for Q₁ or Q₂ or may be a phenyland X⁻ as an anion preferably selected from halide, methyl sulphate andethyl sulphate radicals.

Throughout this discussion of fabric softening agents the expressionhydrocarbyl group refers to alkyl or alkenyl groups optionallysubstituted or interrupted by functional groups such as --OH, --O--,--COHN--, --COO--, etc.

Representative examples of these quaternary softeners include ditallowdimethyl ammonium chloride; ditallow dimethyl ammonium methyl sulphate;dihexadecyl dimethyl ammonium chloride; di(hydrogenated tallow)dimethylammonium methyl sulphate or chloride; di(coconut)dimethyl ammoniumchloride dihexadecyl diethyl ammonium chloride; dibenhenyl dimethylammonium chloride.

Examples of commercially available materials in this class are ARQUAD2C, ARQUAD 2HT, ARQUAD 2T (all Ex Akzo Chemie) and PRAPAGEN WK, PRAPAGENWKT, DODIGEN 1828 (all Hoechst).

2) Diamido Quaternary Ammonium Salts

Diamido quaternary salts of general formula (III) are also known to beuseful as fabric softening agents. ##STR4## Q₆ is a divalent alkylenegroup containing from 1 to 3 carbon atoms. Q₁, Q₂, Q₅ and X⁻ are asdefined previously.

Examples of suitable materials aremethylbis(tallowamidoethyl)(2-hydroxyethyl)ammonium methyl sulphate andmethyl bis(hydrogenated tallowamidoethyl)(2 hydroxyethyl)ammonium methylsulphate. These materials are available from Sherex Chem Co under tradenames VARISOFT 222 and VARISOFT 110 respectively and under the tradename ACCOSOFT from Stepan.

3) Ester Quaternary Ammonium Salts

A number of ester groups containing quaternary ammonium salts, includingthose disclosed in EP 345842 A2 (Procter), EP 239910 (Procter) and U.S.Pat. No. 4,137,180 (Lever) and incorporated herein by reference, areknown to be particularly useful as softening materials. These materialscan be represented by generic formulae (IV) and (V) below. ##STR5##

In formula (IV) Q₇ is a hydrocarbyl group containing 1 to 4 carbonatoms, Q₈ is (CH₂)_(n) --Z--Q₁₀ where n is an integer from 1 to 4 or--Q₁₀. Q₉ is an alkyl or hydroxyalkyl group of 1 to 4 carbon atoms, oris as defined for Q₈. Q₁₀ is a hydrocarbyl group containing from 12 to22 carbon atoms and Y can be --CH(OH)--CH₂ -- or Q₆, as previouslydefined. Z can be --O--C(O)O--, --C(O)O--C(O)--O or --O--C(O)-- and X⁻is an anion.

In formula (V) the symbols Q₂, Q₁₀, and X⁻ have the meanings definedpreviously.

Suitable materials of formula (IV) areN,N-di(stearyl-oxyethyl)-N,N-dimethyl ammonium chloride andN,N-di(stearyl-oxyethyl)-N-hydroxyethyl-N-dimethyl ammonium chloride.Stearyl may be replaced with oleyl, palmityl or tallowyl (mixed chainlength) groups. An illustrative example of a formula (V) material is1,2-ditallowyloxy-3-trimethyl ammoniopropane chloride, which is aditallow ester of 2,3-dihydroxy propane trimethyl ammonium chloride(HOECHST).

4) Quaternary Imidazolinium Salts

A further class of cationic softener materials is the imidazoliniumsalts of generic formula (VI). ##STR6##

Wherein Q₁₁ is a hydrocarbyl group containing from 6 to 24 carbon atoms,G is --N(H)--, or --O--, or NQ₂, n is an integer between 1 and 4, and Q₇is as defined above.

Preferred imidazolinium salts include1-methyl-1-(tallowylamido)ethyl-2tallowyl-4,5 dihydro imidazoliniummethosulphate and1-methyl-1-(palmitoylamido)ethyl-2-octadecyl-4,5-dihydroimidazoliniumchloride. Representative commercially available materials are VARISOFT475 (Sherex) and REWOQUAT W7500 (Rewo).

5) Zwitterionic Fabric Softeners

Other useful ingredients of softening systems include zwitterionicquaternary ammonium compounds such as those disclosed in EP 332270 A2(Unilever) incorporated herein by reference. Representative materials inthis class are illustrated by general formula (XI) and (XII) ##STR7##wherein the groups Q₁₉ are selected independently from Q₇, Q₁₁ and Q₁₄ ;Q₂₀ is a divalent alkylene group containing 1 to 3 carbon atoms and maybe interrupted by --O--, --COHN, --C(O)O--, etc; and Z⁻ is an anionicwater solubilising group (e.g. carboxy, sulphate, sulpho orphosphonium).

Examples of commercially available materials are the EMPIGEN CD and BSseries (Albright Wilson) the REWOTERIC AM series (Rewo) and theTegobetain F, H, L and N series (GOLDSCHMIDT).

6) Nonionic Ingredients

It is well known to blend nonionic materials with cationic, amphotericor zwitterionic softening materials as a means of improving dispersionof the product in rinse waters and enhancing the fabric softeningproperties of the softener blend.

Suitable nonionic adjuncts include lanolin and lanolin derivatives,fatty acids containing from 10 to 18 carbon atoms, esters or fatty acidscontaining from 8 to 24 carbon atoms with monohydric alcohols containingfrom 1 to 3 carbon atoms, and polyhydric alcohols containing 2 to 8carbon atoms such as sucrose, sorbitan, together with alkoxylated fattyacids, alcohols and lanolins containing an average of not more than 7alkylene oxide groups per molecule. Suitable materials have beendisclosed in EP-A-88520 (Unilever), EP-A-122141 (Unilever), GB 2157728A(Unilever), GB 8410321 (Unilever), EP-A-159918 (Unilever), EP-A-159922(Unilever) and EP-A-79746 (Procter).

Fabric softening compositions generally do not contain anionic detergentactive nor bleach, nor detergency building. It is desirable that theamounts (if any) of anionic detergent active, bleach and detergencybuilder are all less than the amount of the fabric softening agent.

A fabric softening composition which is intended to be added to rinsewater may be in the form of a solid, a powder or tablet for instance,which disperses in the rinse water.

More commonly, a fabric softening composition for addition to rinsewater is in the form of a liquid, and is an aqueous dispersion in water.Such a fabric softening composition may contain from 1% or 2% up to 30%or 40% by weight of a fabric softening agent but may contain higherlevels from 40% up to 80% or even 90% by weight in a very concentratedproduct. The composition will usually also contain water, which mayprovide the balance of the composition.

Liquid fabric softening compositions are customarily prepared by meltingthe softening ingredients and adding the melt to hot water, withagitation to disperse the water-insoluble ingredients.

Perfume-carrying particles according to this invention may be added asdry particles or as an aqueous slurry, suitable after the compositionhas cooled.

The amount of perfume incorporated in a fabric softening product willlie in the range from 0.01% to 10% by weight.

For fabric conditioning liquids containing less than 40% by weight offabric softening agent, the amount of perfume is preferably 0.1 to 3% byweight, more preferably 0.1 to 1.5%.

Another form of fabric softening product has a fabric softening agent ina composition which is coated onto a substrate, usually a flexible sheetor sponge, which is capable of releasing the composition in a tumbledryer. Such a product can be designed for single usage or for multipleuses. One such multi-use article comprises a sponge material releasablyenclosing enough of the conditioning composition to effectively impartfabric softness during several drying cycles. The multi-use article canbe made by filling a porous sponge with the composition. In use, thecomposition melts and leaches out through the pores of the sponge tosoften and condition fabrics. A single use sheet may comprise theinventive compositions carried on a flexible substrate such as a sheetof paper or woven or non-woven cloth substrate. When such an article isplaced in an automatic laundry dryer, the heat, moisture, distributionforces and tumbling action of the dryer removes the composition from thesubstrate and deposits it on the fabrics. Substrate materials for singleuse and multiple use articles, and methods of impregnating or coatingthem are discussed in U.S. Pat. No. 5,254,269 and elsewhere.

A fabric softening product which is an impregnated or coated sheet,sponge or other substrate will typically contain perfume-carryingparticles in a quantity to provide from 0.5 to 8% by weight perfume,preferably from 2% or 3% up to 6%.

Personal Washing Products

Perfume-containing particles in accordance with this invention can beutilised in soap bars and in so-called syndet bars which containnon-soap detergent active, but are used for personal washing. Sodiumfatty acyl isethionate is commonly used in this context. In suchproducts the particles may provide from 0.5 to 5% by weight perfume.

Perfume-containing particles in accordance with this invention can beutilised in liquid products for personal washing, such as hair shampoosor shower gels. These typically contain from 2 to 40% by weight ofdetergent active which is anionic, amphoteric, nonionic or a mixture ofthese, especially a mixture in which anionic and/or amphoteric detergentactive provides 2 to 40% by weight of the composition.

Such products will frequently include other materials, especially 0.01to 3% by weight of cationic polymer and/or 0.1 to 10% by weight ofsilicone to deposit on skin or hair.

Again in such products the particles may provide from 0.5 to 5% byweight perfume.

Preferably such liquid compositions will be of desirable viscosities, soas to be pourable or squeezable, and yet will not be so thin that theyrun uncontrollably. The desired viscosity range is approximately 1,000to 15,000 centipoises at room temperature (25° C.) and low shear rate,preferably 3,000 to 6,000 centipoises at 10 sec⁻¹ shear rate.

Household Cleaning Products

The perfume-containing particles of the present invention can also beutilised in household products for cleaning hard surfaces. These areusually aqueous liquids containing detergent active and/or polymericthickener. Other common ingredients are solvents and bleach. The amountof detergent active which is used may vary widely. For some products alow level such as 0.5-3% is appropriate, while others may have more,ranging up to 15% or 20% by weight. Product viscosity will frequentlyexceed 100 centipoise at 10 sec⁻¹ shear rate and a range of 200 to 2000centipoise at 10 sec⁻¹ shear rate is common.

Sunscreening Compositions

The particles may imbibe sunscreening agents, where necessary aftersolution in a carrier oil, such as benzophenones, methyl anthranilate,methoxycinnamates, octocrylene, phenyl salicylates, paraamino benzoylesters, homosalate, benzylidene camphor, phenylbenzimiolazol sulphonicacid and dibenzoylmethane.

"Leave-on" Hair Care, Skin Care, Fabric and Household Compositions

Particles with imbibed perfumes may be used in "leave-on" compositionssuch as hand-creams, skin-creams and lotions, foundation creams,under-arm deodorants and anti-perspirants, in otherwise conventionalaerosol, roll-on, cream and stick formulations, and leave-onhair-conditioners. They may also be formulated in such fabric andhousehold products as fabric fresheners, carpet fresheners, ironing aidsand toilet rim blocks.

The invention will be further explained and exemplified by the followingExamples in which all parts and percentages are by weight, unless statedotherwise.

EXAMPLE 1

A 700 ml reaction flask equipped with motorised stirrer, refluxcondenser, thermometer and inlet tube for delivery from a peristalticpump was placed in a water bath at about 65° C.

An aqueous phase was prepared by mixing hydroxyethyl cellulose (5 parts)and deionized water (168 parts). The hydroxyethyl cellulose had a degreeof substitution of one and was available from Hercules Chemical Corp asNATROSOL 25OL. This phase was mixed until the hydroxyethyl cellulosedissolved and was then charged into the reaction flask. Stirring wasapplied to the reaction flask.

A monomer phase was prepared by mixing iso-butyl methacrylate (70 parts)with a cross linking co-monomer which was 1,6-hexanedioldiacrylate (1.8parts).

2,2'-anzo(bis)isobutyronitrile [usually abbreviated to AIBN] (2 parts)was added directly to the reaction flask and dispersed for about fiveminutes.

The monomer phase was added to the stirring reaction flask using aperistaltic pump over about ninety minutes. After addition the reactionmass was stirred at about 65° C. for about three hours and subsequentlycooled.

The polymer beads were recovered from the aqueous slurry by filtrationand air dried. The beads were sieved to separate the fraction with sizebelow 125 μm.

It can be seen that in this Example, the total quantity ofhydroxy-functional polymer was less than 10% by weight of monomers, andonly part of that quantity becomes attached to the polymer beads.

The cross linking agent is 2% by weight and 1.63% by mole of the monomermixture.

EXAMPLE 2

A 700 ml reaction flask, equipped as in Example 1, was placed in a waterbath at about 65° C.

An aqueous phase was prepared by mixing poly(vinyl alcohol) available asGohsenol AH-22 from Nippon Gohsei British Trades and Shippers Ltd,Dagenham, Essex and having a degree of hydrolysis of 97 to 98.8% (5parts) and deionized water (168 parts). This phase was stirred until thepoly(vinyl alcohol) dissolved and was then charged into the reactionflask. Stirring was applied to the reaction flask.

A monomer phase was prepared by mixing styrene (68 parts) and1,6-hexanedioldiacrylate (1.8 parts).

AIBN (2 parts) was added directly to the reaction flask and dispersedfor about five minutes.

The monomer phase was added to the stirring reaction flask using aperistaltic pump over about ninety minutes. After addition the reactionmass was stirred at about 65° C. for about three hours and subsequentlycooled.

At this stage, the product was in the form of an aqueous slurry fromwhich the polymer beads were recovered by filtration and air dried.

EXAMPLES 3 TO 5

The procedure of Example 2 was repeated with different monomers asfollows:

Example 3: Methyl methacrylate (70 parts) and 1,6-hexanedioldiacrylate(1.8 parts)

Example 4: n-Butylmethacrylate (70 parts) and 1,6-hexanedioldiacrylate(1.8 parts)

Example 5: iso-butylmethacrylate (54 parts) andhydroxypropylmethacrylate (18 parts)

In each of these examples the monomers were satisfactorily converted topolymer beads. These were recovered by filtration and air dried.

EXAMPLE 6

Beads, produced as in Example 5, were sieved to remove any beads largerthan 75 μm diameter.

A perfume was prepared consisting of equal amounts of

i) dihydromyrcenol(2,6-dimethyl-7-octen-2-ol)

ii) anisaldehyde

iii) dimethylbenzylcarbinyl acetate

(iv) 1,1,2,4,4,7-hexamethyl-6-acetyl-1,2,3,4-tetrahydronaphthalene,available under the trademark "TONALID",

(v) 3a,4,5,6,7,7a-hexahydro-4,7-methano-1(3)H-inden-6-ylpropionate,available under the trademark "FLOROCYCLENE",

Perfume-loaded polymer beads were prepared by mixing the above beads andperfume into a diluted rinse conditioner, to yield an aqueous slurrycontaining:

    ______________________________________                                        Polymer beads           10.71%                                                Perfume                 10.71%                                                Dihardened tallow dimethyl                                                    ammonium chloride        3.5%                                                 Water                   Balance                                               ______________________________________                                    

This slurry was agitated for two hours and left to stand for twenty fourhours, after which it appeared that all the perfume had been absorbedinto the polymer beads.

This slurry was added to a quantity of a rinse conditioner formulationwhich was an aqueous emulsion containing a 1,2-dihardenedtallowloxy-3-trimethyl ammoniopropane chloride (HTTMAPC) as cationicsoftener. This material is disclosed in U.S. Pat. No. 4,137,180. Theformulation contained:

    ______________________________________                                        HTTMAPC              13.5%                                                    (including some fatty acid impurity)                                          Ethoxylated Coconut alcohol (20EO)                                                                 0.75%                                                    Hardened tallow alcohol                                                                            0.75%                                                    Calcium chloride      0.2%                                                    Preservative         0.02%                                                    Demineralised water  Balance to                                                                     100%                                                    ______________________________________                                    

After adding the slurry, the resulting perfumed formulation contained0.75% by weight perfume, carried in polymer beads. The perfumed rinseconditioner formulation was agitated for two hours and then stored forsix days in a closed container. A control formulation contained 0.75% byweight perfume, and the same concentration of fabric softener, withoutpolymer beads.

To test perfume deposition, this rinse conditioner formulation and thecontrol formulation were both diluted with water to provide rinseliquors containing 0.5% of the rinse conditioner formulation.

Test pieces of fabric were de-sized cotton terry towelling, approximateweight 25 g. For each test, a piece of terry towelling was weighedaccurately and treated with 30 times its own weight of rinse liquor, ina Tergotometer pot, stirring at 80 rpm for 20 minutes. The cloth wasthen wrung out by hand, and line dried.

The amount of perfume in the fresh and used rinse liquors was determinedby solvent extraction from 100 g of rinse liquor and gas chromatographic(GC) analysis of the solvent extract. The percentage deposition ofperfume materials onto the cloth was calculated for three of the fivematerials. The results obtained were:

    ______________________________________                                                      % Deposition                                                                            Perfume in                                            Ingredient      Control polymer beads                                         ______________________________________                                        Dihydromyrcenol 14      25                                                    DMBCA           24      33                                                    Florocyclene    38      42                                                    ______________________________________                                    

The amount of perfume on the dry cloth was determined by extraction of 5g of dry cloth with 20 ml ethyl acetate, followed by GC analysis of thesolvent extract.

The amount of perfume detected was expressed as a percentage of thetheoretical maximum quantity (which would be present if there werecomplete deposition onto fabric and no subsequent losses).

The results obtained for materials were:

    ______________________________________                                                     % Ingredient remaining on dry                                                 cloth                                                                                     Perfume in                                           Ingredient     Control   polymer beads                                        ______________________________________                                        Dihydromyrcenol                                                                              not detected                                                                            1.3                                                  DMBCA          not detected                                                                            8.0                                                  Florocyclene   not detected                                                                            9.8                                                  Tonalid 2      30.2*     51.1*                                                ______________________________________                                         *= result possibly affected by other GC peaks.                           

EXAMPLE 7

Perfume mixture was incorporated into polymer beads, as set out in theprevious Example, but with two ratios of polymer to perfume. These were1:1 polymer to perfume and 1:2 polymer to perfume.

The resulting perfumed beads were incorporated into rinse conditionerformulations as in the previous example so as to provide 0.75% by weightperfume in each formulation. A control formulation contained 0.75% byweight perfume, but no polymer. These were diluted to rinse liquorscontaining 0.5% by weight fabric conditioner, and used to treat terrytowelling as in the previous Example.

The treated cloths were assessed by a panel of eight people.

Assessments were made on damp cloth directly after treatment, on drycloth 24 hours after treatment and on dry cloth five days aftertreatment.

The assessments were:

    ______________________________________                                        Assessment                                                                             Control    1:1 polymer to                                                                            1:2 polymer to                                Stage    (no polymer)                                                                             perfume     perfume                                       ______________________________________                                        Damp Cloth                                                                             Strongest  Weaker than Weaker than control                                               control     Equal to (1:1)                                                    Equal to (1:2)                                            Dry Cloth (24                                                                          Intense Tonalid                                                                          Florocyclene,                                                                             Florocyclene,                                 hours    odour      Tonalid and Tonalid and                                                       anisaldehyde                                                                              anisaldehyde odours                                               odours      Weaker than (1:1)                                                 Stronger than                                                                 (1:2)                                                     Dry Cloth                                                                              Tonalid odour                                                                            Florocyclene,                                                                             Florocyclene,                                 (five days)         Tonalid and Tonalid and                                                       anisaldehyde                                                                              anisaldehyde odours                                               odours      Stronger than (1:1)                                               Weaker than (1:2)                                         ______________________________________                                    

EXAMPLE 8

Beads were produced as in Example 2. The monomer mixture was isobutylmethacrylate (70 parts) mixed with 1,6-hexanedioldiacrylate (1.8 parts).Preparations were carried out using various different grades ofpolyvinyl alcohol and some other materials as the stabiliser. The gradesof polyvinyl alcohol differed in the extent to which they had beenhydrolysed from polyvinyl acetate.

The materials used were:

    ______________________________________                                        Stabiliser       Hydrolysis Tradename                                         ______________________________________                                        A    polyvinyl alcohol                                                                             98-99%     Gohsenol N-300                                B    polyvinyl alcohol                                                                             97-98.5%   Gohsenol A-300                                C    polyvinyl alcohol                                                                             87-89%     Gohsenol GH-23                                D    polyvinyl alcohol                                                                             78-80%     Gohsenol KH-17                                E    polyvinyl alcohol                                                                             97-99%     Gohsenol AH-22                                     jointly with a surface                                                        active acrylamide                                                             copolymer                                                                F    polyvinyl alcohol                                                                             97-99%     Gohsenol AH-22                                     jointly with a 95:5                                                           copolymer of                                                                  acrylamide and behenyl                                                        (25 ethylene oxide)                                                           methacrylate                                                             G    hydroxyethyl-cellulose     Natrosol 250L                                 H    surface active             MER 10                                             acrylamide copolymer                                                          (comparative example)                                                    ______________________________________                                    

In all cases the dried beads were mixed with their own weight of asingle perfumery material, Florocyclene, also used in Example 6. Aftermixing they were left to equilibrate overnight, then a small quantity offinely divided silica (2% based on the total weight of perfume andpolymer) was added as a surface improving flow aid.

The perfume-containing polymer beads were mixed into rinse conditioner(as used in Example 6) using a magnetic stirrer. In each case the amountof perfume carrying beads was 1.5% by weight of the rinse conditioner,so that the quantity of perfume was 0.75% by weight of the rinseconditioner formulation. A control formulation was prepared containing0.75% Florocyclene without the polymer.

Deposition onto fabric was assessed using test cloths made of cottonterry towelling, acrylic fabric, and polyester. The fabric washingprocedure was the same as set out in Example 6. After treatment of thefabric and drying, the intensity of Florocyclene on groups of the driedtest cloths was assessed by a panel of five assessors who ranked thecloths in order of intensity of Florocyclene. The following results wereobtained as unanimous views of the assessors:

    ______________________________________                                        On cotton test pieces                                                                              B>A>C>Control                                                                 C>D>Control                                                                   E>F>Control                                              and                  G>H>Control                                              On acrylic test pieces                                                                             A>B>C>Control                                            ______________________________________                                    

On polyester test pieces A,B and C were all stronger than the control,but the assessors were not unanimous as to which of the three gave thehighest perfume intensity.

These results demonstrate that the polymer particles A,B,C and D madeusing polyvinyl alcohol as stabiliser and hydroxy-functional monomer allgave an increase in the perceived intensity of perfume on fabric. So didpolymer particles E and F made using polyvinyl alcohol in a mixture ofstabilisers. The polymer particles G made using hydroxyethylcellulose asstabiliser and hydroxy-functional monomer also gave an increase in theperceived intensity of perfume on fabric and were superior to theparticles H made using a different polymer as stabiliser.

EXAMPLE 9

Polymer beads were prepared by the procedure of Example 2, usingisobutyl methacrylate as the sole monomer, without cross-linking agent.

Polymer beads (0.6% by weight) and dimethyl dibenzyl carbinyl acetate(DMBCA) (0.6% by weight) were added to a rinse conditioner formulation(as in Example 6). A control formulation contained 0.6% by weight ofDMBCA, but no polymer beads.

After mixing the formulations, they were left in sealed containers forone week to equilibrate.

To test perfume deposition, the rinse conditioner formulation and thecontrol formulation were both diluted with water to form rinse liquorscontaining 0.3% by weight of the formulation.

These liquors were used to wash terry towelling test pieces, as inExample 6. After drying, the test pieces were assessed for intensity ofDMBCA by a panel of seven assessors. They unanimously considered thatthe DMBCA was present on the cloth with more intensity when polymerbeads were used, compared with the control where no polymer beads wereused.

The same result was obtained using phenylethyl isoamyl ether, availableunder the trade mark ANTHER, in place of DMBCA.

The same result was also obtained using FLOROCYCLENE, as referred to inExample 6, in place of DMBCA.

In a similar procedure the rinse conditioner was dosed with 0.6% polymerbeads and 0.2% of FLOROCYCLENE. The control formulation was dosed with0.6% FLOROCYCLENE only. When the dried test pieces were assessed, theperfume intensity on the cloth from 0.2% FLOROCYCLENE plus 0.6% polymerbeads was greater than the intensity from 0.6% FLOROCYCLENE withoutpolymer beads.

Stability of a preferred rinse conditioner was also tested.

A perfume contained equal weights of

hexanal

d-limonene

phenylethyl alcohol

anisic aldehyde

dimethyl benzylcarbinyl acetate

2,6,6-trimethyl cyclohexadiene carboxylate (ethyl safranate)

5-ethoxycarbonyl-6-isopropyl bicyclo[2,2,1]hept-2-ene (herbanate)

alkyl cyclohexyl propionate

2,2-dimethyl-3(p-ethylphenyl)propanol (floralozone)

This perfume was mixed with and absorbed into polymer beads as above,also into beads as in Example 8G. The weights of polymer and perfumewere equal.

The perfume-loaded beads were mixed into a rinse conditioner formulationas used in Example 6, so as to incorporate 0.75% by weight perfume. As acontrol, the rinse conditioner formulation was mixed with 0.75% byweight of the perfume.

Samples were stored at room temperature of 20° C. or at 37° C. for fourweeks. Then the perfume content was analysed and the condition of theproducts was examined. The results were

    ______________________________________                                        Perfume remaining (wt %)                                                                            Appearance                                              20° C.  37° C.                                                                            20° C.                                                                          37° C.                              ______________________________________                                        Control 55.7       50.0       ok     gelled                                   Example 8G                                                                            64.7       52.3       ok     viscosity                                                                     increased                                Example 9                                                                             66.4       55.3       ok     viscosity                                                                     increased                                ______________________________________                                    

EXAMPLE 10

A laundry detergent powder base was prepared by spray drying some of itsingredients and then adding other to give the formulation tabulatedbelow in which percentages are based on the complete formulation.

    ______________________________________                                                            % w/w                                                     ______________________________________                                        Spray dried                                                                   Linear alkyl benzene sulphonate                                                                     7.00                                                    Sodium tripolyphosphate                                                                             25.00                                                   Acrylic/maleic copolymer                                                                            1.00                                                    Sodium silicate       5.00                                                    Sodium sulphate       25.00                                                   Optical Brightener    0.20                                                    Chelant               0.50                                                    Post-dosed                                                                    Nonionic surfactant (C14-C15 E7)                                                                    4.00                                                    Protease enzyme       1.00                                                    Lipase enzyme         0.30                                                    Tetraacetyl ethylene diamine (TAED)                                                                 4.00                                                    Sodium perborate monohydrate                                                                        16.00                                                   Sodium carbonate      10.00                                                   Suds suppressor       1.00                                                    ______________________________________                                    

A perfume mixture contained equal amounts of:

2-methyl-3(para-t-butylphenyl)propionaldehyde which is available underthe trademark "LILIAL", anisic aldehyde, d-limonene, dodecyl nitrile andhexyl salicylate.

This perfume mixture was mixed with an equal weight of polymer beadsprepared as in Example 5. A small quantity of finely divided silica flowaid was added so as to form a free-flowing powder. This powder was thenadded to the laundry detergent powder base in such a quantity that theresulting composition contained 0.4% of the perfume mixture and 0.4% ofthe polymer beads. A control detergent powder consisted of 0.4% of thisperfume mixture added directly to the above detergent powder base.

The control powder and the test powder were used to wash samples ofdesized cotton terry towelling by the following procedure:

The laundry powder was dissolved at a concentration of 0.7% by weight inwater at 45° C. in a Tergotometer, and mixed for two minutes. Weighedsamples of fabric at a wash solution to cloth ratio of 30:1 were nextadded to the wash liquor and washing was carried out for 20 minutes witha stirrer speed of 100 rpm. The cloths were given a single cold rinsefor ten minutes at the same solution:cloth ratio, then wrung out by handand line dried overnight.

Residual perfume was extracted from the fabric using ethyl acetatecontaining fluoronapthalene as an internal standard. The amounts of twomaterials were determined by gas chromatography into a mass spectrometer(GC-MS) and the results obtained were:

    ______________________________________                                        Perfume Ingredient                                                                            Control (ng/μl)                                                                       Test (ng/μl)                                    ______________________________________                                        lilial          0.44       5.22                                               hexyl salicylate                                                                              2.83       5.45                                               ______________________________________                                    

As can be seen, the use of polymer beads greatly enhanced the amount ofthese two perfume ingredients deposited on the fabric.

EXAMPLE 11

A liquid laundry detergent base was prepared with the followingformulation:

    ______________________________________                                        ingredient           % by weight                                              ______________________________________                                        sodium dodecyl benzene sulphonate                                                                  11.3                                                     sodium lauryl ether sulphate                                                                       3.2                                                      sodium tripolyphosphate                                                                            11.0                                                     sodium pyrophosphate 4.0                                                      sodium carbonate      1.75                                                    fluorescer           0.2                                                      silicone oil antifoam                                                                              0.5                                                      water                balance                                                  ______________________________________                                    

Polymer beads were prepared as in Examples 2 and 8. The monomer mixturewas isobutyl methacrylate (70 parts) mixed with 1,6-hexanedioldiacrylate (1.8 parts) as in Example 8. Preparations were carried outusing two different grades of polyvinyl alcohol as the stabiliser.

The stabilisers were:

A) Polyvinyl alcohol of 87-89% hydrolysis; Gohsenol GH-23.

B) Polyvinyl alcohol of 95-97% hydrolysis; Gohsenol C-500.

Samples of these polymer beads were mixed with their own weight ofFLOROCYCLENE and then the perfume impregnated beads were mixed into thelaundry liquid so as to incorporate 0.4% by weight perfume. A controlliquid contained the perfume added directly without polymer beads.

These liquid compositions were used to wash desized cotton terrytowelling test cloths by the following procedure:

7.5 mls laundry detergent liquid was mixed with 600 mls water at 40° C.for two minutes in a Tergotometer. A 15 g piece of terry towelling wasadded to the Tergotometer pot and agitated in the pot for thirtyminutes. The cloths were then hand wrung and line dried. Further clothswere washed in the same way, but rinsed in 600 mls cold water for twominutes before wringing and line drying.

All the cloths were assessed for FLOROCYCLENE intensity by a panel offour assessors. Assessment was carried out when the cloths were stilldamp and again after the cloths had been left to dry completelyovernight.

At each assessment each assessor graded a control cloth and two testcloths assigning a score of 1 to the most intense, 3 to the leastintense and 2 to the cloth of intermediate intensity. If two clothscould not be distinguished, both were given a halfway score, forinstance 1.5 if the most and medium intensity cloths wereindistinguishable. The results were averaged and are set out in thefollowing table:

    ______________________________________                                                  Beads A   Beads B  Control                                          ______________________________________                                        Damp, no rinse                                                                            1.5         1.5      2.75                                         Dry, no rinse                                                                             2.0         1.0      3.0                                          Damp, with rinse                                                                          2.25        1.0      2.75                                         Dry, with rinse                                                                           2.37        1.0      2.62                                         ______________________________________                                    

EXAMPLE 12

Polymer beads B from the previous Example were impregnated with theirown weight of FLOROCYCLENE and then treated with a small amount offinely divided silica flow aid (4% of the weight of polymer) so as toproduce a free-flowing powder product. These perfume impregnated polymerbeads were then used in the preparation of a hard surface cleaningcomposition and a corresponding control formulation as set out in thefollowing table:

    ______________________________________                                                        Example                                                                              Control                                                ______________________________________                                        Citric acid       3.0      3.0                                                Water             92.75    93.25                                              Nonionic detergent                                                                              3.0      3.0                                                C10 alcohol 7EO                                                               Xanthan gum        0.25     0.25                                              Florocyclene      0.5      0.5                                                Beads Ex 11B      0.5      --                                                 ______________________________________                                    

The compositions were tested by brushing 0.46 mls composition over awhite ceramic tile 15 cm square. One set of tiles was left unrinsed,assessed after 11/2 hours and again after leaving overnight. A secondset of tiles was rinsed with 100 mils distilled water, then assessed.

Assessment was carried out by a panel of five assessors who observedthat the composition with polymer beads led to a more intense odour ineach comparison.

EXAMPLE 13

Polymer beads as used in Example 8G were mixed with their own weight ofphenylethyl isoamyl ether (ANTHER) and then treated with finely dividedsilica flow aid (4% of the weight of the polymer). The resultingperfume-impregnated beads were mixed with a quaternary imidazolinefabric softener (REWOQUAT W7500/H from Sherex) so that the resultingtest composition contained 4% ANTHER.

A control composition was the same quaternary softener mixed with 4%ANTHER, without polymer beads.

Test and control sheet conditioners were made by coating the test andcontrol compositions onto non-woven fabric sheets.

Terry towelling test cloths, 20 cm×20 cm, and other laundry (to addbulk) were washed in unperfumed washing powder and then tumble dried.Each tumble dryer contained a test cloth; several items of otherlaundry, and a sheet impregnated with either the test or the controlcomposition. The tumble dryers were operated on a 50 minutes programme.

After drying, the perfume odour on the terry towelling test cloths wasevaluated by a panel of five people who unaminously considered thatcloths dried along with the test sheets smelt strongly of ANTHER whereasthere was little or no residual ANTHER smell on the cloths dried withcontrol sheets.

EXAMPLE 14

This example illustrates improved deposition and retention of volatileperfume on hair.

A hair shampoo was prepared with the following base formulation:

    ______________________________________                                        ingredient           % by weight                                              ______________________________________                                        sodium lauryl ether sulphate                                                                       9.6                                                      ammonium lauryl ether sulphate                                                                     4.5                                                      sodium chloride      2.0                                                      citric acid          to give pH 6.0-6.5                                       preservative         qs                                                       water                balance to 100%                                          ______________________________________                                    

A light citrus perfume, which would not normally be substantive to hair,was prepared with the following formulation:

    ______________________________________                                                        wt %                                                          ______________________________________                                        Allyl amyl glycollate                                                                            3.0                                                        Citrathal concentrated                                                                           5.3                                                        Linalol           32.0                                                        Linalyl acetate   30.2                                                        Litsea Cubeba Oil  3.0                                                        Orange oil        26.5                                                        ______________________________________                                    

Perfume beads were prepared, generally as in Example 8G, as a 27 wt %slurry in water. This slurry was sieved to exclude any beads larger than125 μm.

The citrus perfume above was added to the slurry in an amount equal tothe weight of polymer in the slurry, then mixed overnight to allow theperfume to be absorbed.

Polymer beads according to Example 8E were also prepared as an aqueousslurry, then air dried and sieved to exclude any beads larger than 125μm. The polymer beads were mixed with finely divided silica flow aid inan amount equal to 4% by weight of the beads. The above citrus perfumewas then mixed with the polymer beads to produce a mixture containingequal weights of polymer and perfume. The resulting mixture was left tostand overnight in a closed container to allow absorption of theperfume.

Perfumed shampoos were prepared by mixing the above shampoo base witheither of the perfumed polymer beads in sufficient quantity that theresulting shampoo contained 1% by weight perfume. A control shampoo wasprepared by mixing 1% of the citrus perfume directly into the shampoo.

The shampoos were tested on hair switches by the following procedure:

Two 12 g hair switches (Yugoslavian Red Tie) were used for each shampoo.Two aliquots, each of one gram, shampoo were measured onto watch glassesfor each shampoo tested. The hair switch was wet under a running tap(˜40° C., flow rate 40 ml/sec) for 5 sec, the first aliquot of shampoowas spread along the hair and massaged into the hair for 30 sec, thenthe switch was rinsed for 20 sec. The second aliquot of shampoo was thenapplied in a similar manner, massaging for 30 sec and rinsing for 30sec. Washed switches were placed in polyethylene bags whilst otherswitches were washed.

The switches were evaluated for perfume intensity while damp, then whenthey were almost dry after 5 hours drying at room temperature, and againafter 24 hours at room temperature. Evaluation was by a panel of fourpeople who scored the switches 1,2 and 3 in order of perfume intensity.Their averaged scores are given in the following table:

    ______________________________________                                                 Control  Example 8G                                                                              Example 8E                                        ______________________________________                                        when damp  3          2         1                                             after 5 hours                                                                            3          2         1                                             after 24 hours                                                                             2.6        2.4     1                                             ______________________________________                                    

EXAMPLE 15

Perfume was encapsulated in an aminoplast resin by the followingprocedure:

2.5 g trimethylolmelamine condensate (Beetle resin PT336 from BritishIndustrial Plastics Ltd) was mixed with 2.5 g of polyvinyl alcohol, 2.8g sodium dihydrogen orthophosphate and 144.7 g water, to form an aqueoussolution which was stirred in a beaker with a magnetic stirrer. Thesolution was adjusted to pH 4.3 with acetic acid, and then the solutionwas stirred at 20° C. for 90 minutes. This aqueous phase was then mixedwith 60 g perfume in a Silverson Mixer and homogenised to an emulsionwhich was stirred for 60 minutes at room temperature. The emulsion wasthen stirred for 20 hours at 40° C. in a vessel with thermometer andcondenser, then raised to 70° C. for three hours. After cooling, themixture was adjusted to pH 8-10 with ammonium hydroxide. The productmixture was an aqueous slurry of aminoplast microcapsules, containingthe perfume. These microcapsules incorporated the hydroxy functionalpolyvinyl alcohol in the aminoplast resin at the surface of thecapsules, so that hydroxy groups of the polymer are available at thesurface of the particles.

The capsules were incorporated into a rinse conditioner formulation asused in Example 6, so as to provide 0.75% perfume in the rinseconditioner.

In a comparative experiment, a polyacrylamide was used in place of thepolyvinyl alcohol. However, addition of the resulting capsules to therinse conditioner caused it to coagulate.

EXAMPLE 16

Acrylate polymer encapsulated within an aminoplast shell was prepared asfollows:

2.5 g trimethylolmelamine condensate (Beetle resin PT336 from BritishIndustrial Plastics Ltd) was mixed with 2.5 g of polyvinyl alcohol, acopolymer of vinyl alcohol and vinyl amine (ratio 88:12), available fromAir products, 2.8 g sodium dihydrogen orthophosphate and 182.2 g water,to form an aqueous solution which was stirred in a beaker with amagnetic stirrer. The solution was adjusted to pH 4.3 with acetic acid,and then the solution was stirred at 20° C. for 90 minutes. 25 gisobutyl methacrylate, 5 g hydroxypropyl methacrylate and 30 g benzylalcohol as solvent mixed together, and 0.6 g of an oil-soluble initiatorwas added. This organic solution was mixed with the aqueous solution andhomogenised to an emulsion, using a Silverson Mixer. The emulsion wasstirred for 60 minutes at room temperature. Next, the emulsion wasstirred for 20 hours at 40° C. in a vessel with thermometer andcondenser, then raised to 70° C. for three hours. After cooling, themixture was adjusted to pH 8-10 with ammonium hydroxide. The productmixture was an aqueous slurry of aminoplast microcapsules, containingthe polymer. These microcapsules incorporated the hydroxy functionalpolyvinyl alcohol in the aminoplast resin at the surface of thecapsules, so that hydroxy groups of the polymer are available at thesurface of the particles.

The slurry of polymer particles, containing about 12% of acrylate corepolymer was mixed with 2-methyl-3(para-t-butylphenyl)propionaldehyde(LILIAL) in an amount equal to the weight of core polymer. The mixturewas stirred for 8 hours, then allowed to equilibrate for 2 days beforeaddition to a rinse conditioner formulation as used in Example 6, so asto provide 0.75% LILIAL in the rinse conditioner.

The resulting rinse conditioner was added at a concentration of 0.3% byweight to 600 ml water, and used to rinse a terry towelling test cloths,whose weight was measured accurately and close to 20 g. The cloth wasrinsed in a tergotometer for 20 minutes, hand wrung so that theliquid:cloth ratio was 2:1 and line dried overnight. LILIAL wasextracted from the dry cloth and determined by gas chromatography.

A similar preparation and test was carried out using a copolymer with a94:6 ratio of vinyl alcohol and vinyl amine. A control test was carriedout using perfume but no polymer beads.

The weights found on the cloths were:

    ______________________________________                                        Mg/g cloth                                                                                   after drying                                                                  overnight 2 days later                                         ______________________________________                                        Control           1.5        Not measured                                     beads with 88:12 copolymer                                                                     14.7        Not measured                                     beads with 94:6 copolymer                                                                      17.7        12.6                                             ______________________________________                                    

Particles were prepared generally as above, using 90 g of an oil inplace of the 30 g benzyl alcohol. The perfume odour was found to persiston the fabric during drying, much better than a control where theperfume was not carried by polymer particles.

EXAMPLE 17

A shower gel base was prepared with the following formulation:

    ______________________________________                                                            wt %                                                      ______________________________________                                        Sodium lauryl ether (2EO) sulphate                                                                  16.8                                                    Coconut diethanolamide                                                                               1.5                                                    Sodium chloride        2.0                                                    EDTA sodium salt       0.1                                                    Preservative          q.s.                                                    Citric acid           to pH 6 to 6.5                                          Water                 balance to 100%                                         ______________________________________                                    

A control formulation contained 1.0% by weight of a perfume, of thefollowing composition:

    ______________________________________                                                           wt %                                                       ______________________________________                                        Dodecanal             1.25                                                    Methylnonyl aldehyde 2.5                                                      Allyl amyl glycollate                                                                              1.5                                                      Anethole synthetic   0.2                                                      Benzyl salicylate    15.00                                                    Carvone laero        0.1                                                      Cedramber            4.4                                                      cis-3-hexenyl salicylate                                                                            0.50                                                    Citronellol standard 2.5                                                      Coumarin             1.0                                                      Damascone alpha      1.0                                                      Dihydro myrcenol     12.0                                                     Dipropylene glycol    6.38                                                    Eugenol              0.8                                                      Tonalid              9.0                                                      Heliotropin          0.7                                                      Hexyl cinnamic aldehyde                                                                            12.4                                                     Lavandin oil         0.7                                                      Lilial               8.0                                                      Linalol              4.0                                                      Methyl dihydro jasrnonate                                                                          7.0                                                      Oakmoss synthetic    0.3                                                      Para t-butyl cyclo hexyl acetate                                                                   6.0                                                      Patchouli oil        2.5                                                      Undecalactone gamma  1.2                                                      ______________________________________                                    

A test formulation contained particles prepared as in Example 16, using94:6 vinyl alcohol/vinyl amine copolymer prepared as in Example 16,containing the same perfume in a weight ratio of 1:1 perfume:corepolymer. The formulation was prepared by including an aqueous slurry ofthe particles in a quantity of the shower gel base, so as to include 1%by weight of perfume.

The control and test shower gels were evaluated by the followingprocedure:

Washing Protocol/Evaluation

The shower gel was applied by a second person to the subject's arms. 1gram of each shower gel was weighed onto watch glasses. The water flowand temperature from a mixer tap was set up such that the watertemperature was ˜40° C. and the flow was ˜100 ml/sec. The tap was leftrunning throughout the whole experiment. The left forearm was held underthe running water for ˜5 seconds and the first shower gel scooped fromthe watch glass and applied to left forearm, keeping the arm out of theflow of water. The shower gel was lathered by rubbing it up and down theforearm for a total of 20 times, then the gel was rinsed off under theflowing tap by moving the arm up and down for a total of 10 times. Theskin was patted dry with a clean towel. The whole process was thenrepeated for the second shower gel on the right arm.

The arms were then evaluated over time for perfume odour by a panel offour expert assessors, scoring on a scale of 0 (no perfume) to 20 (verystrong perfume) as follows:

    ______________________________________                                                        Average Scores                                                Elapsed Time      Control Test                                                ______________________________________                                        Initial           10.0    12.7                                                1 hour            8.5     10.0                                                31/2 hours        3.2      5.3                                                6 hours           0.3      2.2                                                ______________________________________                                         Sunscreen example                                                        

EXAMPLE 18

For this example, polymer beads of the following composition wereproduced using the procedure of example 2-isobutyl methacrylate (98parts), 1,6-hexanedioldiacrylate (2 parts), the polyvinyl alcohol beingGohsenol GH-20. These yielded a 25 wt % slurry of beads with a meanparticle size of approximately 25 μm into which was then stirred anequal weight of Parsol MCX* (equal to the dry weight of the polymer) toproduce the particles containing sunscreen.

These sunscreen particles were then incorporated into the followingshampoo formulation to give a shampoo with improved deposition ofsunscreen to the hair:

    ______________________________________                                                            wt %                                                      ______________________________________                                        EMPICOL ESB 3 (i)     35.00                                                   TEXAPON ALS (ii)      15.00                                                   SODIUM CHLORIDE        1.00                                                   PURIFIED WATER        to 100.00                                               Sunscreen/Polymerparticles                                                                           1.0                                                    Polyquartenium-10 (iii)                                                                              0.70                                                   CITRIC ACID           to pH 6.0-6.5                                           ______________________________________                                         (i) ex Albright & Wilson, Cumbria, England                                    (ii) ex Henkel Chemicals Ltd, Henkel House, Middlesex, England                (iii) Celquat SC240 ex National Starch and Chemical Co.                  

We claim:
 1. Water-insoluble solid particles containing a solid organicpolymer core, the core having attached at its exterior a solid furtherpolymer to form an at least partial coating on said core which ispermeable to liquid, said further polymer incorporating tree hydroxygroups, and being present quantity which is no more than 25% of theweight of the particles, with liquid absorbed in said particle. 2.Particles according to claim 1 wherein the liquid is hydrophobic or is amixture of liquids at least one of which is hydrophobic.
 3. Particlesaccording to claim 2 wherein the core of organic polymer is enclosedwithin a polymer shell, said further polymer incorporating hydroxygroups being present at the exterior of the shell.
 4. Particlesaccording to claim 2 wherein the organic polymer is a polymer of a vinylmonomer.
 5. Particles according to claim 4 wherein the organic polymeris a polymer of one or more monomers which are acrylic and/or alkylacrylic esters, of formula ##STR8## wherein R₁ is hydrogen or linear orbranched alkyl of 1 to 6 carbon atoms and R₂ is linear or branched alkylof 1 to 8 carbon atoms.
 6. Particles according to claim 1 wherein saidfurther polymer is a polymer or copolymer of vinyl alcohol.
 7. Particlesaccording to claim 6 wherein said further polymer is polyvinyl alcohol.8. Particles according to claim 1 wherein said further polymer iscellulose or chemically modified cellulose.
 9. Particles according toclaim 5 wherein R₁ is hydrogen or methyl, R₂ is linear or branched alkylof 3 or 4 carbon atoms and said further polymer is polyvinyl alcoholwhich is at least 88% hydrolysed from polyvinyl acetate.
 10. Particlesaccording to claim 1 with a mean size in the range 10 to 100 μm. 11.Particles according to claim 1 which are solid particles, wherein theliquid is a perfume.
 12. A product comprising particles according toclaim
 1. 13. A product according to claim 12 which is a liquidcomposition including detergent active and/or thickener.
 14. A productaccording to claim 12 which is a solid laundry detergent composition forfabric washing, containing from 5 to 50% by weight of one or moredetergent active compounds, and from 5 to 60% by weight of detergencybuilder, and from 0.1 to 1.5% by weight of perfume.
 15. A productaccording to claim 12 which is a liquid laundry detergent compositionfor fabric washing, containing from 5 to 30% by weight of one or moredetergent active compounds, from 5 to 40% by weight of detergencybuilder, water and from 0.1 to 1.5% by weight of perfume.
 16. A productaccording to claim 12 which is a rinse conditioning liquid containingfrom 1 to 40% by weight of a fabric softening agent as a suspension inwater, and containing 0.1 to 3% by weight perfume.
 17. A productaccording to claim 12 which is a solid substrate impregnated or coatedwith a fabric softening composition, and containing from 2 to 8% perfumeby weight based on the fabric softening composition.
 18. A productaccording to claim 12 which is in the form of a bar for personalwashing, wherein perfume containing particles provide from 0.5 to 5% byweight of perfume.
 19. A product according to claim 12 which is in theform of a liquid for personal washing, containing 2 to 40% by weightdetergent and from 0.5 to 5% by weight of perfume.
 20. A productaccording to claim 12 which is a stay-on cosmetic product.
 21. Asunscreen product which is a composition or article containing particlesaccording to claim 1 wherein the liquid is a sunscreening agent.
 22. Amethod of making particles according to claim 1 which comprises, aftercompletion of the polymerization of the particles, placing them incontact with the liquid and causing or allowing absorption of the liquidinto the solid particles.